Coprecipitation of nickel and silicate salts from aqueous solutions in the presence of porous silica or alumina particles to increase the surface area of a catalyst was first disclosed in U.S. Pat. No. 3,371,050 to Taylor and Sinfelt. It was later discovered by J. L. Carter (U.S. Pat. Nos. 3,697,445; 3,859,370 and 3,868,332) that controlled addition of sodium metasilicate in the process of the '050 patent further increases the total surface area of the catalyst as well as the reduced nickel surface area thereby enhancing the catalytic activity of such catalysts. Carter and Barnett (U.S. Pat. No. 4,251,672) later found that the addition of copper salts during coprecipitation enables one to reduce the catalyst at 200.degree. C. rather than at 400.degree. C. and concurrently achieve relatively high hydrogenation activities. Subsequently, Carter, Barnett, and Sinfelt (U.S. Pat. No. 4,263,255) found that by a judicious blend of nickel, cobalt and copper salts during coprecipitation in the presence of sodium metasilicate and kieselguhr, produced a catalyst having extremely high catalytic activities when the catalyst is reduced at 200.degree. C. However, the catalytic activity of such trimetallic catalyst dramatically falls off when the catalyst is reduced at 400.degree. C.
Recently, Halluin and Barnett (U.S. Pat. Nos. 4,273,680 and 4,273,929) discovered that by replacement of the sodium metasilicate in the process of U.S. Pat. No. 3,697,445 with aluminum salts one enhances the catalytic hydrogenation activity of the catalyst. The activity is further enhanced if small amounts of magnesium salts are added during coprecipitation (U.S. Pat. No. 4,307,248 to Barnett and Halluin). Such a pronounced enhancement in activity, however, was not manifested in the catalyst when copper and/or cobalt salts were added during coprecipitation, particularly those metal blend catalysts which were reduced at 200.degree. C.